This is a widespread, polymorphic species, long known by different names in various parts of its range.

Perennial, rhizomatous. Culms loosely tufted, sometimes stoloniferous and rooting at lower nodes, 60–100 cm tall, nodes bearded or glabrous. Leaf sheaths glabrous or sparsely to densely pilose with tubercle-based hairs; leaf blades broadly linear, 5–20 × 0.5–1.5 cm, pubescent, rarely glabrescent, base rounded to subcordate, apex acute; ligule 1–2 mm. Racemes (2–)3–6 or more, mostly terminal, subdigitate, 2–9 cm; rachis internodes and pedicels broadly linear, triquetrous, ciliate on outer angle, shortly ciliate on inner angles. Sessile spikelet lanceolate, 4–5 × 1.2–1.4 mm; lower glume leathery with expanded rounded flanks below middle, herbaceous, strongly veined and sharply 2-keeled above, glabrous or villous, keels usually winged, apex 2-toothed; upper glume attenuate into mucro or awnlet to 2 mm; awn of upper lemma 1.2–1.5 cm. Pedicelled spikelet laterally compressed, similar to sessile, upper lemma awned.

Guangdong, Guizhou, Yunnan [India, Malaysia, Myanmar, Sri Lanka, Thailand; Africa, Mauritius, Pacific Islands].

Moist places on grassy plains and hillsides; 100–400 m.

Ischaemum digitatum Brongniart; I. duthiei Stapf ex Bor; I. fasciculatum Brongniart.

Perennials, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems terete, round in cross section, or polygonal, Stems branching above base or distally at nodes, Stem nodes bearded or hairy, Stem internodes solid or spongy, Stem internodes hollow, Stems with inflorescence le ss than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades 1-2 cm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence a dense slender spike-like panicle or raceme, branches contracted, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence a panicle with digitately arranged spicate branches, Inflorescence with 2-10 branches, Inflorescence branches 1-sided, Inflorescence branches paired or digitate at a single node, Inflorescence branches paired racemes, V-sh aped, Flowers bisexual, Flowers unisexual, Spikelets pedicellate, Spikelets sessile or subsessile, Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 2 florets, Spikelets paired at rachis nodes, Spikelets in paired units, 1 sessile, 1 pedicellate, Pedicellate spikelet well developed, staminate, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets secund, in rows on one side of rachis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes equal to or longer than adjacent lemma, Glumes awned, awn 1-5 mm or longer, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma 1 nerved, Lemma 3 nerved, Lemma 5-7 nerved, Lemma glabrous, Lemma apex dentate, 2-fid, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn 1-2 cm long, Lemma awn from sinus of bifid apex, Lemma awn once geniculate, bent once, Lemma margins thin, lying flat, Lem ma straight, Callus or base of lemma evidently hairy, Callus hairs shorter than lemma, Palea present, well developed, Palea membranous, hyaline, Palea about equal to lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.

Ischaemum polystachyum, the paddle grass, is a species of perennial in the family Poaceae. It is a common species found in New Guinea and the Pacific Islands, and is often found on roadsides and in gardens. It has become an invasive species in Pohnpei, Micronesia, where it was first introduced as cattle fodder.